SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b5a153aa765a6f8b6ea437f8cc57e777ea7f4e909d158c68e7b20085720d3de' 
  AND token = 'B4nqh3uVhPffSch/A4V1swQXShCKWSybmertLwtIbik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}